Around 50 firefighters are still working to contain the Swansea fire which caused traffic chaos in the city yesterday and sent plumes of black smoke billowing across the sky.

And police are continuing to warn people living near the former Mettoys factory at the Fforestfach industrial estate, where the fire broke out at lunchtime on Thursday, to stay indoors and keep doors and windows shut.

Environment Agency officials have deployed a boom and other pollution control equipment at a nearby stream to lessen the impact of contaminated firewater.

It is believed hundreds of tonnes of shredded rubber from tyres caught fire.

Mid and West Wales fire fighters using 11 appliances have the fire under control but are continuing to make sure it is contained to the disused factory site.

South Wales Police said today: “Air quality measurements taken from near the scene of the fire show the concentration of pollutants in the smoke have the potential to irritate eyes, nose and throat and cause an impact on health if inhaled.

“There is greater potential for health problems in people with existing chest and lung problems such as asthma, chronic bronchitis and cardiac problems including angina.

“Local residents are advised to minimise exposure by staying indoors and closing windows and doors.

“Local air quality continues to be monitored to determine ongoing public health impacts. “Anyone with symptoms who is concerned should try to avoid the affected area and contact NHS Direct Wales on 0845 46 57 or their GP.”

Environment Agency Wales is working to protect the local Fforestfach Stream and officials have deployed a booms and other equipment to minimise any pollution.

They are also continuing to monitor the stream as well as air quality of the wider area.

A police spokesman said: “The Agency is assisting Mid and West Wales Fire and Rescue Service with its response by providing technical advice and helping to contain any potentially contaminated firewater.

“Ystrad Road, Bruce Road, Kingsway and the Queensway on the industrial estate are currently closed to traffic.

“Appropriate diversionary signs are in place to advise road users of alternative routes

“The Fforestfach Industrial Estate also remains closed to vehicles.

“The emergency services are assisting some local businesses to gain temporary access to their premises and are working to restore vehicle access to the industrial estate as soon as possible and to enable vehicles to be removed from the Park and Ride Service, which remains suspended until further notice.”

A multi-agency Serious Incident Room has been set up at Swansea Central Police Station.